Piston skirt expander



Patented May 7, 1935 I uNTED STATES PATENT OFFICE 2,000,106 rs'roN s xmr ExrANDEa Balph It. Teetor, Hagerstown, 'I'he Perfect Circle Company,

Ind., assignor to Hagerstown, Ind.,

My invention relates to means'for expanding split skirts ofl p' tons for internal combustion enl gines and the like.

The principal object of my invention is to prog vide a simple and novehexpander formed of flat 'spring metal.

Another object the expande'r with novel expansion formations.

Still another object of my invention is to provide an elongated spring expander which is' which .are readilyy formed of interlocking sections assembled and, easily inserted into a pistonjskirt.

Further objects and advantages of my invention will appear from the following description taken in conjunction I'with drawing in which:

Figure is a bottompan view of a piston hav;

'- ingone form'of \my' improved expander applied thereto; Y

Fig. 2 is a perspective view of the expander shown in Fig. 1; cv I Fig. 3 is a perspective view of a modified form of embodiment of the inventionin a two-part expander; Flgs. 4 and 5, respectively, are perspective views of modified forms ofthe invention as embodied in one-piece expanders; and

Fig. 6 is a Vfragmentary perspective view of a` modified form of joint between two meeting edges `of the expander. f

Referring to ,Fig 1, piston skirt 'I is provided with a vertical slot /8 and piston 'pin bosses 9 i through which extends the usual piston pin IO.

- The piston may types, such, for example, as is shown in my United' 1,885,038, issued October 2s,

be lof any of the well-known States Patent No. '1932. In most pistons formed of aluminum or the like, the head is wholly or partially separated from the skirt by a circumferential slot or slots and the skirt is provided with a vertical slot to permit it to expand and contract. It is in this general type of piston that my invention is peculiarly adaptedfor use.

The expander illustrated in Figs. l and 2 comprises two complementary and similar half-sec.- tions iz and 1 3 formed from fiat spring metal. The end edges ll of the parallel sides of theY sections abut and have 'laterally displaced interlocking lugs 12'* and l3b. It will be observed by referring to Fig. 1, that when the expander is assembled and mounted in the skirt of the piston, the parallel sides of the expander' press'against the facing ends of the piston pin bosses 9 and the piston pin Ill then projects through the openings li (Fig. 2) in the sides of the expander. Each of my invention is to provide.

the accompanylng taining the axis of I the latter having two skirt as at the points provided with S- haped or double folds or formations l1 which include IS. The exhander is also expansion 4 .the points IS. Thesides ofthe expander adjacent the pin g provided with vertical I! of the expander befolds IS and IB are bosses 9 are preferably folds l8 and the portions tween the adjacent pairs of preferably. semi-circular.

'When. the expander is to be'applied toV the skirt, the two half sections are brought together with their lugs l'ia and l3b interlocking; the expander is compressed or contracted lengthwise and crosswise and while in this condition it is inserted into the skirt,' and it is then released. 15 With the expander in position, it vwill be ap-l parent that its sides press firmly'in opposite4 dlrections against the bosses 9 and that the points IS press firmly against the interior of the piston skirt. Thus the expander tends to expand the skirt so that it at all times snugly fitsthe cylinder wall. The expansion folds aiford the de-v sired action in accomplishing this result.

The 'expander is particularly useful inworn pistons though it is susceptible of use in new 25, pistons.

In the modified form ofl embodiment shown in Fig. 3, thetwo half sections IZ and l3 are formed somewhat differently from the sections of the first formshownin Figs. 1 and 2, in that in the form shown in Fig, 3, each half has one complete side and the edgesI abut at either side of the piston pin and not in' thev vertical plane conthe piston pin as in .the flrst In Fig. 3, one edge of each section has an with openings 23 24 on the adjacent form. overlying -flange ,22 provided into which extend locking lugs edge of the' 'other section. v In the form illustrated in Fig. 4, the expander is of the same general shape as those shown in Figs. 1, 2 and 3 but,in the Fig. 4' form, the expander is made from a continuous strip, one edge of which i`s Qbent .to provide a channel 25 in which the other edge' is seated. The latter edge is also provided with two lugs 26 extending through .45 openings in the channel 25. Fig. 6 illustrates a. form of joint comprising a channel 2' in one edge to receive the other edge, lugs 21fl extending over.` and below the ends of the channel. 5 Fig. 5 shows an expander which is similar in general contour to those shown in the other figures but which is formed from a tube or a conjoints.

It will be apparent from the foregoing that an expander embodying my invention is simple in structure, cheap to manufacture, easy. to assemble and efficient in use. Further modifications may be indulged in without departing from the spirit of the invention.

I claim: I

'1. A one-piece piston skirt expander formed of flat spring metal and forming a continuous integral oblong figure having a plurality of spaced apart' expansion folds adjacent each end.

2. A piston skirt expander comprising 'twoI complemental sections having their end edges abutting and provided with interlocking means at said edges and with expansible formations.

3. A piston skirt expander formed of fiat spring metal and generally oblong in shape, the expander being split forming end edges the end edges abutting and interlocking, and the expander having expansible formations.

4. `A piston skirt expander formed of two spring metal sections, and generally oblong in shape, with the sides provided with openings to receive a piston pin, the edges of the two sections abutting in a vertical plane containing the centers 1of said openings.

5. A piston skirt expander formed of two spring metal sections, each generally U-shaped and having spaced expansion folds, the end edges of the two sections having interlocking-Projections.

6. In combination with a piston having a split skirt, an expander formed of spring metal and generally oblong in shape and' contacting with the piston skirt at spaced points intermediate the pin bosses, the expander having reverse expansion folds including each of said points.

7. In combination with a piston having a split skirt and piston pin bosses, an expander comprising two U-shaped sections having their end edges ,abutting and provided with interlocking means, the sides of the expander engaging said bosses and pressing outwardly thereagainst and each section of the expander being provided with reverse expansion folds intermediate its ends.

8. In combination with a piston having a split skirt and piston pin bosses, an expander formed of fiat spring metal and generally oblong in shape and having parallel sides adapted to press against the facing edges of said bosses, the ends of the expander being adapted to engage the piston skirt intermediate the bosses and each side of the expander having vertical yielding formations Aadjacent the pin bosses.

9. A piston skirt expander formed of fiat spring metal and generally oblong in shape and of closed figuration and having S-shaped formations including the points at which the expander engages the skirt.

10. A piston skirt expander of generally oblong shape and closed figuration and comprising two complemental sections with means for interlocking their ends together.

RALPH R. TEETOR. 

